Information processing apparatus, printing apparatus, and information processing method

ABSTRACT

A characteristic value of a printing medium to be printed is measured with an optical sensor. A type of a printing medium is extracted based on reference characteristic values and a measured value, and the type of the printing medium is informed by an input/output unit. The reference characteristic value associated with the type of the printing medium determined to be used in a printing apparatus is changed.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an information processing apparatus, aprinting apparatus, an information processing method, and a program.

Description of the Related Art

When printing is performed with a printing apparatus, it is known thatprinting is performed by using controlled parameters appropriate for atype of printing medium. Japanese Patent Laid-Open No. 2016-215591describes that, in order to perform printing by using appropriatecontrolled parameters, a plurality of characteristic values of aprinting medium to be printed is measured and the type of the printingmedium is identified by making a comparison with reference values.

However, errors of a sensor that measures the characteristic values of aprinting medium, individual differences among printing media,differences in measurement environment, and the like, influence measuredvalues, so the type of a printing medium may not be identified withsufficient accuracy when references prepared in advance are used.

The present invention accurately identifies the type of a printingmedium.

SUMMARY OF THE INVENTION

An information processing apparatus includes an acquisition unit, adecision unit, an input unit, a determination unit, and a change unit.The acquisition unit is configured to acquire a measurement resultobtained by measuring a characteristic value of a printing medium with ameasuring unit. The printing medium is to be printed with a printingunit. The decision unit is configured to decide a candidate for a typeof the printing medium based on the measurement result of the printingmedium, acquired by the acquisition unit, and a reference characteristicvalue of each of types of printing media set in advance to identify atype of the measured printing medium. The input unit is configured toinput information associated with the type of the printing medium to beprinted with the printing unit. The determination unit is configured todetermine whether to change the reference characteristic value of thetype of the printing medium associated with the information input by theinput unit based on the measurement result of the printing medium andthe type of the printing medium associated with the information input bythe input unit. The change unit is configured to, when the determinationunit determines to change the reference characteristic value of the typeof the printing medium associated with the information input by theinput unit, change the reference characteristic value of the type of theprinting medium associated with the information input by the input unitbased on the measurement result of the printing medium.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B are perspective views showing the configuration of aprinting apparatus according to a first embodiment.

FIG. 2 is a view showing the configuration of a carriage according tothe first embodiment.

FIG. 3 is a view showing the configuration of an optical sensor in thefirst embodiment.

FIG. 4 is a diagram showing the block configuration of a control systemof the printing apparatus in the first embodiment.

FIG. 5 is a flowchart showing a printing medium determination process inthe first embodiment.

FIG. 6A to FIG. 6E are views showing display modes of an input/outputunit in the first embodiment.

FIG. 7A and FIG. 7B are tables showing characteristic values stored inan EEPROM in the first embodiment.

FIG. 8A to FIG. 8C are views showing other modes of the input/outputunit.

FIG. 9 is a table showing an example of measured values that aremeasured in the first embodiment.

FIG. 10 is a table showing determination results in the printing mediumdetermination process of the first embodiment.

FIG. 11A and FIG. 11B are tables showing priority assignment in thefirst embodiment.

FIG. 12A to FIG. 12D are tables for illustrating a method of calculatinga characteristic value in the first embodiment.

FIG. 13 is a flowchart showing a printing medium determination processin a second embodiment.

FIG. 14 is a table showing history information in the second embodiment.

FIG. 15 is a view showing a display mode of an input/output unit in thesecond embodiment.

FIG. 16A and FIG. 16B are tables showing correction values and correctedcharacteristic values in a fourth embodiment.

FIG. 17 is a flowchart showing a process of updating a correction valuein the fourth embodiment.

FIG. 18A and FIG. 18B are tables showing correction values in the fourthembodiment.

FIG. 19 is a flowchart showing a printing medium determination processin a fifth embodiment.

FIG. 20A to FIG. 20C are tables showing characteristic values stored inan EEPROM in the fifth embodiment.

FIG. 21 is a flowchart showing a correction value updating process inthe fifth embodiment.

FIG. 22 is a flowchart showing an extraction range changing process inthe fifth embodiment.

FIG. 23 is a flowchart showing a resetting process in a sixthembodiment.

FIG. 24A to FIG. 24H are views showing display modes of an input/outputunit in the sixth embodiment.

FIG. 25 is a flowchart showing a process of resetting estimated data inthe sixth embodiment.

FIG. 26 is a flowchart showing a process of resetting printing mediuminformation in the sixth embodiment.

FIG. 27 is a flowchart showing a process of resetting for each of typesof printing media in the sixth embodiment.

DESCRIPTION OF THE EMBODIMENTS First Embodiment Overall Configuration

FIG. 1A and FIG. 1B are perspective views showing the configuration of aprinting apparatus 100 equipped with casters and a basket for sheetdischarge. FIG. 1A shows the overall outer appearance. FIG. 1B shows aninternal structure with a top cover open. The printing apparatus 100 inthe present embodiment prints by applying ink droplets as a recordingagent onto a printing medium with an ink jet printing method. A printingmedium is conveyed in a conveyance direction set to a Y direction. Anink jet printing apparatus including a so-called serial printing headwill be described. With the serial printing head, a carriage 101 onwhich a printing head 102 is mounted prints while reciprocally moving inan X direction that intersects with the Y direction. Alternatively, anink jet printing apparatus including a so-called line printing head maybe used. With the line printing head, an array of nozzles is providedover a printing width for conveying a printing medium. Alternatively, amultifunctional peripheral apparatus (MFP) that integrates not only aprinting function but also a scanning function, a facsimile function, asending function, or the like, may be used. Alternatively, anelectrophotographic printing apparatus that uses powder toner as arecording agent may be used. In the present embodiment, the function ofan information processing apparatus for executing a process ofdetermining a printing medium to be used (described later) is equippedfor the printing apparatus 100.

The printing apparatus 100 has an input/output unit 406 at its top. Theinput/output unit 406 is an operation panel and shows an ink level andcandidates for a type of a printing medium on a display. When a useroperates keys on the input/output unit 406, the user is able to select atype of a printing medium or configure the settings for printing.

The carriage 101 includes an optical sensor 201 (FIG. 2) and theprinting head 102. The printing head 102 has a discharge port face atwhich discharge ports for discharging ink are provided. The carriage 101is configured to be reciprocally movable in the X direction (carriagemoving direction) along a shaft 104 via a carriage belt 103 by beingdriven by a carriage motor 415 (FIG. 4). In the present embodiment, theprinting apparatus 100 is able to acquire a diffused reflectioncharacteristic value or a specular reflection characteristic value andmeasure a distance between the carriage 101 and a printing medium 105with the use of the optical sensor 201.

The printing medium 105, such as rolled paper, is conveyed on a platen106 in the Y direction by a conveyor roller (not shown). While thecarriage 101 is moving in the X direction above the printing medium 105conveyed on the platen 106 by the conveyor roller, ink droplets aredischarged from the printing head 102. Thus, printing operation isperformed. As the carriage 101 moves to an end of printing area on theprinting medium 105, the conveyor roller conveys the printing medium 105by a certain amount and moves the carriage 101 to a position at whichthe printing head 102 is able to print on an area to be subjected to thenext scanning and printing. Through a repetition of the above-describedoperations, an image is printed.

Configuration of Carriage

FIG. 2 is a view that shows the configuration of the carriage 101. Thecarriage 101 includes a translator 202 and a head holder 203. The headholder 203 holds the printing head 102 and the optical sensor 201 thatis a reflection sensor. As shown in FIG. 2, the optical sensor 201 isconfigured such that a bottom face is equal to or higher in level thanthe bottom face of the printing head 102.

Configuration of Optical Sensor

FIG. 3 is a schematic cross-sectional view showing the configuration ofthe optical sensor 201. The optical sensor 201 includes a first LED 301,a second LED 302, a third LED 303, a first photodiode 304, a secondphotodiode 305, and a third photodiode 306 as optical elements. Thefirst LED 301 is a light source having an angle of irradiation of anormal line (90°) to the surface (measurement surface) of the printingmedium 105. The first photodiode 304 receives light irradiated from thefirst LED 301 and reflected from the printing medium 105 at an angle of45° with respect to the Z direction. In other words, an optical systemthat detects a so-called diffused reflection component of reflectedlight from the printing medium 105 is formed.

The second LED 302 is a light source having an angle of irradiation of60° to the surface (measurement surface) of the printing medium 105 withrespect to the Z direction. The first photodiode 304 receives lightirradiated from the second LED 302 and reflected from the printingmedium 105 at an angle of 60° with respect to the Z direction. In otherwords, an angle of emitting light and an angle of receiving light areequal to each other, and an optical system that detects a so-calledspecular reflection component of reflected light from the printingmedium 105.

The third LED 303 is a light source having an angle of irradiation of anormal line (90°) to the surface (measurement surface) of the printingmedium 105. The second photodiode 305 and the third photodiode 306 eachreceive light irradiated from the third LED 303 and reflected from theprinting medium 105. The second photodiode 305 and the third photodiode306 each operate as a range sensor that measures a distance between theoptical sensor 201 and the printing medium 105 because the amount oflight received changes with a distance between the optical sensor 201and the printing medium 105.

In the present embodiment, the optical sensor 201 is installed on thecarriage 101. An optical sensor may be provided in another mode. Forexample, an optical sensor may be fixed to the printing apparatus 100 ormay be a measurement device for measuring a characteristic value, suchas a diffused reflection value and a specular reflection value, of aprinting medium, separated from the printing apparatus 100, and may bein a mode to send a characteristic value measured by the measurementdevice to the printing apparatus 100. In the present embodiment, theoptical sensor 201 is installed on the carriage; however, another modemay be employed. For example, an optical sensor may be fixed to theprinting apparatus 100 or may be a measurement device for measuring acharacteristic value, such as a diffused reflection value and a specularreflection value, of a printing medium, separated from the printingapparatus 100, and may be in a mode to send a characteristic valuemeasured by the measurement device to the printing apparatus 100.

Block Chart

FIG. 4 is a diagram showing the block configuration of a control systemof the printing apparatus 100. A ROM 402 is a non-volatile memory. Forexample, a control program for controlling the printing apparatus 100 ora program for implementing the operations of the present embodiment arestored in the ROM 402. The operations of the present embodiment are, forexample, implemented when the CPU 401 reads the program stored in theROM 402 and runs the program by loading the program onto the RAM 403.The RAM 403 is also used as a working memory of the CPU 401. The EEPROM404 stores data to be held even when the power of the printing apparatus100 is turned off. At least the CPU 401 and the ROM 402 implement thefunction of the information processing apparatus for executing aprinting medium determination process (described later). The EEPROM 404stores characteristic values of each of printing media, which are usedas predetermined references, and categories of the printing media.Categories are those roughly classified from types of printing media. Inthe present embodiment, five categories, that is, glossy paper, plainpaper, coated paper, photo paper, film paper, and special, are set. Forexample, types of printing media are classified into a glossy papercategory when a printing medium is standard glossy paper, and areclassified into a plain paper when a printing medium is premium plainpaper. Recording media also include a medium that is not a paper medium;however, in the present embodiment, the word “paper” is used andprovided to a user. History information or characteristic values ofprinting media may be stored in not a storage medium in the printingapparatus 100 but an external memory, such as a ROM of a host computerand a server.

An interface (I/F) circuit 410 connects the printing apparatus 100 and anetwork, such as an external LAN. The printing apparatus 100 sends orreceives various jobs, data, and the like, to or from an apparatus, suchas an external host computer, through the I/F circuit 410.

The input/output unit 406 includes an input unit and an output unit. Theinput unit receives an instruction to turn on the power from a user, aninstruction to perform printing, and an instruction to set variousfunctions. The output unit displays various device information, such aspower-saving mode, or a settings screen for various functions that theprinting apparatus 100 is able to execute. In the present embodiment,the input/output unit 406 is the operation panel provided in theprinting apparatus 100, and the input/output unit 406 is connected to asystem bus 416 via an input/output control circuit 405 so as to be ableto send or receive data to or from the system bus 416. In the presentembodiment, the CPU 401 executes control to provide information aboutthe output unit.

Alternatively, the input unit may be a keyboard of an external hostcomputer and may be configured to be able to receive an instruction of auser from the external host computer. The output unit may be a displayconnected to an LED display, an LCD display, or a host apparatus.Alternatively, when the input/output unit 406 is a touch panel, theinput/output unit 406 is able to receive an instruction from a user witha software key. Alternatively, the input/output unit 406 may be aspeaker and a microphone, may use input from a user as voice input, andmay use information to be provided to a user as voice output.

The information processing apparatus that includes a CPU and a ROMhaving similar functions to those of the CPU 401 and the ROM 402 andthat is externally connected to the printing apparatus 100 may execute aprinting medium determination process (described later) and determine aprinting medium to be used in the printing apparatus 100.

When measurement is performed with the optical sensor 201, an LEDcontrol circuit 407 is driven by the CPU 401, and a predetermined LED inthe optical sensor 201 is controlled so as to light up. Each of thephotodiodes of the optical sensor 201 outputs a signal commensurate withreceived light. The output signal is converted to a digital signal by anA/D conversion circuit 408 and is once saved in the RAM 403. Data to besaved is stored in the EEPROM 404 when the power of the printingapparatus 100 is turned off.

The printing head control circuit 411 supplies a drive signalcommensurate with printing data to a nozzle drive circuit includingselectors and switches mounted on the printing head 102 and controlsprinting operation of the printing head 102, such as the drivingsequence of nozzles. For example, when data to be printed is sent fromthe outside to the I/F circuit 410, the data to be printed is once savedin the RAM 403. The printing head control circuit 411 drives theprinting head 102 based on printing data converted from data to beprinted to printing data for printing. After that, an LF (line feed)motor drive circuit 412 drives an LF motor 413 based on the bandwidth ofprinting data, and the like, and a conveyor roller connected to the LFmotor 413 rotates to convey a printing medium. A CR (carriage) motordrive circuit 414 causes the carriage 101 to scan via the carriage belt103 by driving the CR (carriage) motor 415.

Data that is sent from the I/F circuit 410 contains not only data to beprinted but also data of details set by a printer driver. Data to beprinted can be, for example, received from the outside via the i/Fcircuit 410 and stored in a storage unit or stored in advance in astorage unit, such as a hard disk. The CPU 401 reads image data from thestorage unit, controls an image processing circuit 409, and converts(binarizing process) the image data into printing data to use theprinting head 102. The image processing circuit 409, other than thebinarizing process, executes various image processing, color spaceconversion, HV conversion, gamma correction, and rotation of image.

Overall Flow

FIG. 5 is a flowchart showing the printing medium determination processof acquiring measurement results obtained by measuring thecharacteristic values of the printing medium 105 to be printed,providing candidates for a printing medium to the input/output unit 406based on the measurement results and set reference characteristicvalues, and determining a type of the printing medium 105 to be printed.In the following printing medium determination process, measured valuesare obtained as new information for the characteristic values of a typeof a printing medium, selected by a user, and characteristic values setin advance are changed based on the measured values so as to be broughtclose to the measured values. Through such learning, characteristicvalues with which a type of a printing medium can be more accuratelyselected are obtained.

The processes of step S101 to step S114 are implemented, for example,when the CPU 401 shown in FIG. 4 reads the program stored in the ROM 402onto the RAM 403 and runs the program. The printing medium determinationprocess may be executed by software on the host apparatus. In thepresent embodiment, since the input/output unit 406 is the operationpanel provided in the printing apparatus 100, candidates for a printingmedium are informed by displaying the names of printing media on theoperation panel. The input/output unit 406 may be a combination of thehost apparatus and the display connected to the host apparatus. When theinput/output unit 406 is a speaker that has a microphone function andthat is able to input or output voice, candidates for a printing mediumare informed through the speaker, and a printing medium is selected by auser inputting the name of the printing medium or an associatedreference sign by voice to the microphone.

As the CPU 401 receives an instruction to start sheet feed from a userthrough the operation panel that is the input/output unit 406, the CPU401 executes a process of feeding the printing medium 105. FIG. 6A is anexample of display on the operation panel to wait for input of aninstruction to start the sheet feed process. The operation panel is atouch panel with which a user is able to make touch input. When “YES” istouched, sheet feed is started.

When “YES” is selected in FIG. 6A and sheet feed is started, theprinting medium 105 is conveyed by the conveyor roller to a positionwhere the optical sensor 201 is able to detect the printing medium 105on the platen 106. After the printing medium 105 is conveyed, thecarriage 101 moves in the X direction above the printing medium 105, andthe diffused reflection value, specular reflection value, and thickness(hereinafter, paper thickness) of the printing medium 105 are acquiredwith the optical sensor 201 (step S101). A diffused reflection valuecorresponds to the whiteness of a printing medium. A specular reflectionvalue corresponds to the glossiness of a printing medium. The printingmedium determination process may be executed by using the width of aprinting medium in the X direction as one of the characteristics of theprinting medium. A position where the characteristics of a printingmedium are measured may be one, or an average of measurement results atmultiple points may be used. Measurement of the characteristics may beperformed in a state where the optical sensor 201 is stopped or may beperformed while the optical sensor 201 is being moved. Measured valuesare once stored in a memory such as the RAM 403.

Subsequently, the CPU 401 reads the acquired measured values from thememory and compares the measured values with the predeterminedcharacteristic values of various printing media, stored in the EEPROM404 (step S102). Thus, a type of a printing medium of which a degree towhich the characteristic values fall under the characteristics indicatedby the measured values is higher than a predetermined degree isextracted. Details will be described below. FIG. 7A shows thecharacteristic values of each of the types of printing media, stored inthe EEPROM 404. The characteristic values=T₀ when the characteristicvalues are initial values at the present. These values are set forreference values, and the type of the printing medium is identified bycomparing the measured values with the reference values. The ranges ofthe reference values are defined as detection ranges. The detectionranges are extraction ranges for extracting a candidate for a printingmedium to be informed to a user. Hereinafter, the detection ranges arereferred to as extraction ranges. Diffused reflection values andspecular reflection values are values obtained by converting an outputvoltage from analog to digital with 10 bits. The output voltage is avoltage that the optical sensor 201 outputs upon receiving light. Eachextraction range is a range from a minimum value (min value) to amaximum value (max value) with a center set to a middle value of each ofcharacteristic values of a printing medium. An extraction range of ±50μm from a central value is set for paper thickness, and a type of aprinting medium of which the acquired paper thickness falls within theextraction range is extracted (step S103).

It is determined whether there is any type of printing medium extracted(step S104).

When there is no type of printing medium extracted, all the categoriesare displayed on the operation panel as shown in FIG. 6B (step S114).The categories are arranged in a predetermined order and displayed. Inthe case where the categories are displayed, when a category selected bya user is input, the types of printing media in the category aredisplayed as shown in FIG. 6C. Then, of the types of printing mediadisplayed, input of the selected type of printing medium is received.The input is made by touching the name of the printing medium displayed.FIG. 6B shows “ALL” at the bottom in addition to the categories ofprinting media. When “ALL” is selected, all the printing media aredisplayed in a predetermined order. Recording media may be displayed inrecent order, that is, in order from the latest used printing medium.

When there is a type of printing medium extracted in step S104, a typeof printing medium of which the acquired diffused reflection value fallswithin the extraction range of diffused reflection value, stored in thestorage unit (EEPROM) 404, is extracted (step S105). As shown in FIG.7A, the extraction range of diffused reflection value is a range of ±5from the central value. Here, it is determined whether there is a typeof printing medium extracted (step S106). When there is no appropriatetype of printing medium, categories are displayed on the operation panelas shown in FIG. 6B (step S114).

When there is a type of printing medium extracted in step S106, a typeof printing medium of which the acquired specular reflection value fallswithin the extraction range of specular reflection value, stored in thestoring unit (EEPROM) 404, is extracted (step S107). As shown in FIG.7A, the extraction range of specular reflection value is a range of ±5from the central value. Here, it is determined whether there is a typeof printing medium extracted (step S108). When there is no appropriatetype of printing medium, categories are displayed on the operation panelas shown in FIG. 6B (step S114).

When there is a type of printing medium extracted in step S108, theextracted type of printing medium is assigned with a priority such thata printing medium of which the characteristic values are closer to themeasured values is set for a printing medium having a higher priority(step S109). A method of determining the order of display will bedescribed in detail later.

As shown in FIG. 6D, the names of the types of printing media aredisplayed from the top in descending order of priority determined instep S109 (step S110).

When an icon 40 displayed on the operation panel in FIG. 6D is touched,display of the screen can be scrolled downward. When “STOP” is touched,the printing medium determination process is cancelled, and display ofFIG. 6A is switched to display of a home screen. FIG. 6D shows the namesof printing media in descending order of priority with codes 1 to 3prefixed to the names of printing media. Selection of a type of printingmedium is made by touching any one of the names of printing mediadisplayed. Here, the priority of standard half-glossy paper to whichnumber 1 is assigned is the highest. Codes may be any codes as long asthe codes can indicate the level of priority, and may be codes otherthan numerals. A display method is not limited thereto and may be anymethod as long as a user can recognize the order of priority.

In FIG. 6D, candidates for a printing medium can be displayed up tothree from the top; however, since the number of the extracted types ofprinting media is two, only two printing media are displayed in FIG. 6D.A user is informed that there is no third candidate by displaying “NOAVAILABLE CHOICE” in the third field in light color (or dark color) soas to be less attractive than the names of the above-described twoprinting media. For example, when the background color of the operationpanel is black, two printing media are displayed in white color and thetext “NO AVAILABLE CHOICE” is displayed in gray color lower inbrightness than white color. Categories of paper are displayed below thetext “NO AVAILABLE CHOICE”. In this way, when a printing medium that auser desires is not included in printing media displayed on theinput/output unit 406, an individual printing medium is allowed to beselected in order to select a printing medium of another type. In thepresent embodiment, the category to which a type of printing medium inthe first place belongs is displayed at the top. By displayingcategories having close characteristics at higher levels to make it easyto select those categories, even when a printing medium that a userdesires is not included in candidates for a printing medium, time andeffort that take until the category of a desired printing medium isselected can be reduced.

FIG. 8A to FIG. 8C show methods of displaying candidates for a type ofprinting medium on the input/output unit 406 in other modes. As shown inFIG. 8A, when not all the candidates for a type of printing medium canbe displayed on the operation panel, the input/output unit 406 may beconfigured such that a lower-level candidate can be displayed throughscroll operation, or the like. Alternatively, candidates do not need tobe displayed in order from the upper level as long as a user canrecognize the order of priority. The name of the highest-level printingmedium may be displayed at the center of the operation panel.Alternatively, as shown in FIG. 8B, the level of priority may beindicated by increasing the size of characters representing the name ofa printing medium having a higher level of priority or displaying thecharacters in boldface. Categories are displayed below the text “PAPERCATEGORY”; however, categories may be displayed without any text meaning“PAPER CATEGORY”. Alternatively, not categories but types of printingmedia other than candidates for a printing medium may be displayed belowthe candidates.

Alternatively, as shown in FIG. 8C, only a printing medium having apriority in the first place may be displayed. When a user desires toselect another one of extracted printing media, the user can select aportion of the item of the printing medium displayed as standard plainpaper in FIG. 8C. A display method may be configured such that, when theselection is input, the screen appears as shown in FIG. 6D and anotherprinting medium can be selected.

When there is no type of printing medium extracted in step S108, onlycategories are displayed as shown in FIG. 6C (step S114).

When a user selects a type of printing medium on the input/output unit406 in step S111, it is determined in step S112 whether the measuredvalues fall within the learning ranges of the selected printing medium.The learning ranges will be described here. If learning is performedbased on a measured value significantly different from a characteristicvalue set in advance (or changed through a learning process), a wrongvalue is learned, so a learning range that is the range of a measuredvalue to be learned is set. A learning range is twice as large as anextraction range in the present embodiment. A learning range is a rangefor changing a characteristic value. When a measured value falls withinthe learning range of a selected printing medium, the characteristicvalue is changed based on the measured value. In the present embodiment,a learning range is a range of a predetermined value from the centralvalue of a characteristic value and is a range of a value twice as largeas the difference between the central value and the minimum value or thedifference between the central value and the maximum value. For example,the extraction range of specular reflection value of standard glossypaper in FIG. 7A is from 95 to 105, that is, ±5 from the central value.Since the learning range takes on a range of ±10 from the central value,that is, twice as large as ±5, the learning range is from 90 to 110.Similarly, a diffused reflection value and a paper thickness each alsotake on a range twice as wide as the extraction range, so the learningrange of diffused reflection value of standard glossy paper is from 90to 110, and the learning range of paper thickness is from 90 to 290. Thelearning range is not limited thereto and may take on, for example, thesame range as the extraction range or may be set to a learning rangethat varies among characteristics or types of printing media. When themeasured values fall within the learning ranges of the selected type ofprinting medium, the process proceeds to step S113. In step S113, thecharacteristic values of the type of printing medium, selected in stepS111, are updated with values changed based on the measured values, andthe changed values are stored in the EEPROM 404. As described above, theprinting medium determination process ends. When the measured values donot fall within the learning ranges, the printing medium determinationprocess is ended without updating the characteristic values of theselected type of printing medium. An update of characteristic valueswill be described in detail later.

When the printing medium determination process ends and a printingpreparation completes, the CPU 401 is in a state of waiting for aprinting job from a user, and, upon receiving a printing job, startsprinting. When the type of printing medium selected and input by a userfrom the input/output unit 406 is different from the type of printingmedium in a job sent from a host computer to the printing apparatus 100,the CPU 401 may be configured not to update the characteristic values ofthe printing medium, stored in the EEPROM 404.

In the printing medium determination process of FIG. 5, a type of printmedium having an appropriate paper thickness is extracted in step S103,a type of print medium having an appropriate diffused reflection valueis extracted in step S105, and a type of printing medium having anappropriate specular reflection value is extracted in step S107. Thesequence to be extracted is not limited thereto, and, for example, atype of printing medium having an appropriate diffused reflection valuemay be extracted first.

When the optical sensor 201 is provided in a measurement deviceseparated from the printing apparatus 100, the following mode isapplicable. The characteristics of a printing medium set in themeasurement device are measured first. Then, the acquired measuredvalues are sent to the printing apparatus 100, a printing medium isextracted by the CPU 401 of the printing apparatus 100, and a candidateis provided to the input/output unit 406.

A method of determining the order of display of step S110 of theprinting medium determination process and an update of thecharacteristic values of step S113 will be described below by way of aspecific example. As shown in FIG. 9, the characteristics of theprinting medium acquired in step S101 are (diffused reflection value,specular reflection value, paper thickness)=(103, 98, 225). FIG. 10 is atable showing determination results of the processes of step S103 tostep S107. “APPLICABLE” represents a printing medium of which themeasured value falls within the extraction range. “NOT APPLICABLE”represents a printing medium of which the measured value does not fallwithin the extraction range. A printing medium of which at least one ofcharacteristic values does not fall within the extraction range is notsubjected to determination in the next process. This is shown in FIG. 10as “NOT DETERMINED”.

In step S103, standard glossy paper, standard half-glossy paper, premiumglossy paper, and thick glossy paper, which are the types of printingmedia of which the acquired paper thickness (here, 190) falls within theextraction range of paper thickness shown in FIG. 7A, are extracted.Since there are the extracted types of printing media, affirmativedetermination is made in step S104, and the process proceeds to stepS105.

In step S105, from among the printing media extracted in step S103,standard glossy paper, standard half-glossy paper, and thick glossypaper, which are the types of printing media of which the measureddiffused reflection value (here, 103) falls within the extraction rangeof diffused reflection value shown in FIG. 7A, are extracted. Sincethere are the extracted types of printing media, affirmativedetermination is made in step S106, and the process proceeds to stepS107.

In step S107, from among the printing media extracted in step S105,printing media of which the measured specular reflection value (here,98) falls within the extraction range of specular reflection value shownin FIG. 7A, are extracted. Here, standard glossy paper, standardhalf-glossy paper, and thick glossy paper are extracted. Since there arethe extracted printing media, affirmative determination is made in stepS108, and the process proceeds to step S109.

In step S109, the printing media are assigned with priorities such thatthe printing medium of which the characteristic values are closer to themeasured values has a higher order of priority. Then, in step S110, thenames of the extracted types of printing media are displayed from thetop in order from the printing medium having a higher order of priority.

FIG. 11A and FIG. 11B are tables for illustrating a method ofdetermining the order in step S109. In the present embodiment, thecloseness between the central value and measured value of eachcharacteristic is calculated with the following calculation method.

|(Measured value−Central value of characteristic)/(Maximum value ofcharacteristic−Central value of characteristic)|

A minimum value may be used instead of the maximum value of thecharacteristic.

For example, when the specular reflection value of standard glossy paperis calculated, |(103−100)/(105−95)|=0.6. The above-described calculationis performed for the types of printing media extracted in step S105, andthe values of closeness to the measured values of the characteristicsare added. A printing medium having a less total value hascharacteristic values closer to the measured values. It is determinedthat a printing medium having a less total value is a type of ahigher-level printing medium, and display is performed on theinput/output unit 406 accordingly. Here, as shown in FIG. 6E, display isperformed in order of standard glossy paper, thick glossy paper, andstandard half-glossy paper.

The process of step S112 in the case where standard half-glossy paperthat is displayed in the third place is selected by a user in step S111will be described.

In step S112, it is determined whether the measured values acquired instep S101 fall within the learning ranges of standard half-glossy paperthat is the selected type of printing medium. When the measured valuesfall within the learning ranges of all the characteristics, that is,diffused reflection value, specular reflection value, and paperthickness, it is determined that the measured values fall within thelearning ranges of standard half-glossy paper. As shown in FIG. 7A, theextraction range of specular reflection value of standard half-glossypaper is from 94 to 104 that is a range of ±5 from the central value(middle) set to 99. As described above, the learning range takes on arange twice as wide as the extraction range from the same central valueas the extraction range. The learning range of specular reflection valueof standard half-glossy paper is from 89 to 109 that is a range of ±10from the central value set to 99. Similarly, the learning range ofdiffused reflection value of standard half-glossy paper is from 85 to105, and the learning range of paper thickness is from 90 to 290. Sinceall the measured values (diffused reflection value, specular reflectionvalue, paper thickness)=(103, 98, 225) fall within the above-describedlearning ranges, the process proceeds to step S113.

In step S113, the characteristic values of the type of printing mediumselected are updated based on the measured values. The characteristicvalues shown in FIG. 7A are characteristic values before update. FIG. 9shows measured values. In the present embodiment, the characteristicvalues of the type of printing medium are brought close to the measuredvalues by a set percentage. Because the measured values containmeasurement errors, the characteristic values may be rather changed suchthat the differences between the measured values and the characteristicvalues are reduced in a stepwise manner through learning multiple times,that is, the differences reduce by a set percentage, than thecharacteristic values are directly replaced with the measured values ata time. One example of that is expressed by a generalized formula asfollows.

Updated characteristic values (T _(n+1))=(Measured values(R)−Characteristic values (T _(n)))×α+Pre-updated characteristic values(T _(n))

Here, α is a value that indicates a percentage by which characteristicvalues are brought close to measured values. When the percentage ofreduction in difference is set to 25%, the central value of specularreflection value is as follows. For example, when T_(n)=T₀ (initialvalue), T₁ is found through the first update.

When R=103 and T_(n)=T₀=99, T₁ is found as follows.

T ₁=(103−99)×0.25+99=100

Similarly, the characteristic values of diffused reflection value andpaper thickness are updated. The updated results are shown in FIG. 7B.The fact that the extraction ranges of specular reflection value anddiffused reflection value each are ±5 from the central value and theextraction range of paper thickness is ±50 from the central valueremains unchanged, and minimum values and maximum values are alsoupdated according to central values. The original characteristic valuesare overwritten with the updated characteristic values. The updatedcharacteristic values are stored as the characteristic values ofstandard half-glossy paper in the EEPROM 404, and used in subsequentprinting medium determination processes. Thus, the printing mediumdetermination process ends.

In the above-described example, when the characteristic values areupdated, the characteristic values are bought close to the measuredvalues by 25%; however, the percentage of reduction in difference is notlimited thereto and may be a percentage higher than 0% and lower than orequal to 100%. The percentage of reduction in difference may be set foreach type of printing medium or may be set for each characteristic.

In a state where the characteristic values are updated as shown in FIG.7B, standard half-glossy paper of which the characteristics of aprinting medium are (diffused reflection value, specular reflectionvalue, paper thickness)=(103, 98, 225) is measured again. The results ofpriority assignment in order of closeness of the characteristic valuesto the measured values are shown in FIG. 11B. As a result of the updateof the characteristic values of standard half-glossy paper, standardhalf-glossy paper is ordered in the first place. Therefore, in stepS110, standard half-glossy paper that is the measured printing medium isdisplayed on the input/output unit 406 as the highest-level printingmedium, and a user can more easily select the printing medium.

Alternatively, as another method of incorporating measured values intocharacteristic values of a type of printing medium, an average value oflast N measured values may be set as each characteristic value. FIG. 12Ato FIG. 12D are tables for illustrating a method of setting acharacteristic value by using last three measured values. Here, thespecular reflection value of standard half-glossy paper will bedescribed as an example. FIG. 12A shows the case where standardhalf-glossy paper is not selected even once in step S111 or step S114.In FIG. 12A, 99 that is an initially set value is input as last threevalues, and the average value is also 99, so the characteristic value is99. In FIG. 12B, when standard half-glossy paper is selected, themeasured value 103 is input as the last measured value. The averagevalue 100.3 at the time when the measured value 103 is input is set asthe characteristic value that is used subsequently. FIG. 12C shows thecase where standard half-glossy paper is further selected, and 104 isinput as the last measured value. The average value at this time, thatis, 102, is set as the characteristic value to be used subsequently.FIG. 12D shows the case where standard half-glossy paper is furtherselected in the state of FIG. 12C, and 102 is input as the last measuredvalue. The average value 103 at this time is set as the characteristicvalue to be used subsequently.

As described above, measured values of a fed printing medium areacquired, and a type of printing medium of which the characteristicvalues are closer to the measured values is informed at a higher level.With this configuration, a type of printing medium that a user is morelikely to select is preferentially informed, so time and effort at thetime of selecting a type of printing medium that a user desires can bereduced.

Second Embodiment

In the first embodiment, extracted types of printing media are informedin order of closeness of characteristic values to measured values. Inthe present embodiment, the order of informing is determined based onhistory information.

In the present embodiment, the EEPROM 404 stores a history of types ofprinting media, fed and selected by a user so far. The printing mediaselected by a user are the printing media selected in step S111 of FIG.5 of the first embodiment. The stored information is treated as historyinformation.

FIG. 13 shows a flowchart of a printing medium determination process ofthe present embodiment. Similar processes are executed in step S201 tostep S208, and step S217 in FIG. 13 to those of step S101 to step S108,and step S114 in FIG. 5 of the first embodiment.

In step S209, it is determined whether the extracted type of printingmedium is included in a usage history based on the history informationstored in the EEPROM 404. The EEPROM 404 stores printing media used inthe printing apparatus 100 so far in association with informationindicating the closeness of timing used as shown in FIG. 14. When aprinting medium of the same type is used multiple times, onlyinformation about the last usage is entered into the history. FIG. 14shows that a printing medium of which a number assigned to the field ofhistorical order is smaller is a more recently used printing medium.

When the type of printing medium extracted in step S209 is not includedin the history information, the extracted type of printing medium isassigned with a priority in step S215 as in the case of step S109 ofFIG. 5 such that a printing medium of which the characteristic valuesare closer to the measured values is set for a printing medium having ahigher order of priority.

In step S216, the names of printing media are displayed in order on theoperation panel as shown in FIG. 6D in accordance with the order ofpriority determined in step S215, and the process proceeds to step S211.

When the type of printing medium extracted in step S209 is included inthe history information, the extracted type of printing medium isdisplayed in step S210 such that printing media of the same type arecollectively displayed as one as shown in FIG. 15. In FIG. 15, the typesof printing media used so far are displayed such that a more recentlyused printing medium is a printing medium having a higher order ofpriority and the name of printing medium having a higher order ofpriority is displayed in order from the top. Here, the names of printingmedia of three types can be displayed; however, only printing media oftwo types extracted and included in the history information aredisplayed. In this case, information indicating that there is no historyinformation like “NO AVAILABLE CHOICE” is displayed in the third field.

Similar processes are executed in step S211 to step S213 to those ofstep S111 to step S113 in FIG. 5. When a user selects a type of printingmedium on the input/output unit 406 in step S211, it is determined instep S212 whether measured values fall within the learning ranges of theselected printing medium. When the measured values do not fall withinthe learning ranges of the selected printing medium, the processproceeds to step S214. When the measured values fall within the learningranges of the selected printing medium, the characteristic values of theselected printing medium are changed and updated based on the measuredvalues in step S213.

Subsequently, in step S214, the history information is updated withinformation in which the selected type of printing medium is enteredinto the latest usage history. Thus, the printing medium determinationprocess of the present embodiment ends.

When the measured values do not fall within the learning ranges of theselected printing medium (NO in step S212), the CPU 401 may beconfigured not to update the history information in step S214.

As described above, in the present embodiment, types of printing mediathat have been used before are informed as higher-level candidates. Withthis configuration, a printing medium of a type that a user is morelikely to use is preferentially informed, so time and effort at the timeof selecting a printing medium that a user desires can be reduced.

Third Embodiment

In the first embodiment, characteristic values of types of printingmedia, stored in the EEPROM 404, are directly corrected, and thecorrected characteristic values are compared with measured values. Inthe present embodiment, correction values are provided in addition tocharacteristic values of types of printing media, stored in the EEPROM404. Correction values are updated through learning, but characteristicvalues are not changed from T₀ that are initial values. Values obtainedby correcting the characteristic values T₀ with the correction valuesC_(n) are used as reference characteristic values and are compared withmeasured values. Correction values take on C₀ as initial values and thenth correction values are C_(n). Similar portions to those of the firstembodiment are omitted.

In a printing medium determination process of the present embodiment,similar processes to those of the first embodiment are executed in stepS101, step S103 to step S112, and step S114 in FIG. 5. Here, step S102and step S113 will be mainly described.

In addition to characteristic values of types of printing media,correction values for correcting the characteristic values are stored inthe EEPROM 404. At the time of making a comparison with measured values,corrected characteristic values are calculated based on predeterminedcharacteristic values shown in FIG. 7A and correction values andcompared with the measured values. In the present embodiment, referencecharacteristic values at the time of making a comparison with measuredvalues are set to T₀+C_(n) that are obtained by adding thecharacteristic values T₀ and the correction values C_(n).

In step S102, the measured values acquired in step S101 are comparedwith the corrected characteristic values of the types of printing media.The processes of step S103 to step S112 are executed by using thereference characteristic values T₀+C_(n) calculated in step S102.

In step S113, the correction values for the characteristic values of theprinting medium selected by a user are updated with learned values. Thecorrection values are updated such that the corrected characteristicvalues of the type of printing medium are brought close to the measuredvalues by a set percentage. This example is expressed as follows by ageneralized formula. α indicates a percentage of reduction indifference.

Updated correction values (C _(n+1))=(Measured values (R)−Referencecharacteristic values (T ₀ +C _(n)))×α+Pre-updated correction values (C_(n))

Fourth Embodiment

In the above-described embodiment, characteristic values at the time ofmaking a comparison with measured values are corrected through learningfor a selected type of printing medium, and printing media not selectedby a user are not corrected through learning at that time. In thepresent embodiment, when it is determined that characteristic valuesvary depending on the individual difference of an optical sensor and anenvironment in which the apparatus is installed, characteristic valuesof non-selected types of printing media are also corrected. The presentembodiment will be described as a mode in which characteristic valuesare not changed from the initial values T₀ as in the case of the thirdembodiment and correction values for correcting the characteristicvalues of types of printing media are provided. Similar portions tothose of the above-described embodiment are omitted.

Individual correction values for each of types of printing media andcommon correction values for commonly correcting the characteristicvalues of all the types of printing media are stored in the EEPROM 404.An example of stored correction values is shown in FIG. 16A. As shown inFIG. 16A, individual correction values for each of types of printingmedia are set. Premium plain paper has not been selected as a printingmedium for use, so no correction values are set. Common correctionvalues are set for a specular reflection characteristic, but no commoncorrection values are set for a diffused reflection characteristic or apaper thickness characteristic.

Corrected characteristic values obtained by correcting thecharacteristic values of printing media shown in FIG. 7A with thecorrection values of FIG. 16A are shown in FIG. 16B. A correctedspecular reflection value of standard glossy paper is from 97 to 107,obtained by adding an individual correction value of +1 and a commoncorrection value of +1 to the range of 95 to 105 that is a referencespecular reflection value of standard glossy paper. A corrected diffusedreflection value of standard glossy paper is from 99 to 109, obtained bythe addition of an individual correction value of +4. In the presentembodiment, results obtained by adding the reference characteristicvalues, individual correction values, and common correction values ofeach printing medium are described as corrected characteristic values;however, corrected reference values may be calculated with a methodother than addition. For example, individual correction values andcommon correction values may be saved as coefficients, and valuesobtained by multiplying reference characteristic values of a printingmedium by the individual correction values and the common correctionvalues may be used as corrected reference values.

In the process of generating correction values in step S113 of FIG. 5 ofthe first embodiment, individual correction values and common correctionvalues are generated in the present embodiment. FIG. 17 shows aflowchart of the process of generating correction values of the presentembodiment.

In step S1501, the individual correction values for the characteristicvalues of the printing medium selected by a user are updated withlearned values. The individual correction values are updated such thatthe corrected characteristic values of the type of printing medium arebrought close to the measured values by a set percentage. A similarprocess to the process described in step S113 of FIG. 5 of the secondembodiment is executed.

In step S1502, it is determined whether the number of types of printingmedia for which individual correction values are set is greater than orequal to a predetermined number. When the number of types of printingmedia for which individual correction values are set is greater than orequal to the predetermined number, whether there is a common tendency incorrection can be determined based on the individual correction values,so the process proceeds to step S1503. When the number of types ofprinting media for which individual correction values are set is notgreater than or equal to the predetermined number, whether there is acommon tendency in correction cannot be determined because the number oftypes for which individual correction values are set is small, so theprocess is ended.

In step S1503, it is determined whether the percentage of the number ofindividual correction values in the same direction in all the individualcorrection values in the same item among the individual correctionvalues in the same item, set for the printing media, exceeds apredetermined percentage. The direction of correction is a positivedirection when a correction value is positive or a negative directionwhen a correction value is negative. In the present embodiment, thepredetermined percentage is set to 70%. When, of the types of printingmedia for which individual correction values are set, the number of thetype of printing media of which the correction is in the same directionis higher than or equal to 70%, it is determined that there is a commontendency in correction, and the process proceeds to step S1504. When thecorrection in the same direction is less than 70%, it is determined thatthere is no common tendency in correction, and the process is ended.

In step S1504, common correction values are updated. Common correctionvalues are set based on individual correction values of the types ofprinting media determined as corrections in the same direction, that is,the types of printing media included in 70% in step S1503. The smallestvalues of the set individual correction values are set as commoncorrection values.

When common correction values are set in step S1504, the individualcorrection values are updated based on the set common correction valuesin step S1505. The individual correction values of printing media forwhich no individual correction values are set are not updated.

The process of FIG. 17 will be described by way of a specific example asfollows.

FIG. 18A shows correction values when the process of step S1501 of FIG.17 is executed. FIG. 18B shows correction values after the process ofFIG. 17 is executed.

In step S1501, the correction values for the characteristic values ofthe printing medium set by a user are updated with learned values. Theupdated correction values are shown in FIG. 18A. Here, individualcorrection values for standard glossy paper, standard half-glossy paper,premium glossy paper, and thick glossy paper are set.

In step S1502, it is determined whether individual correction values ofwhich the number is greater than or equal to the predetermined numberare set. In the present embodiment, the predetermined number is set tofour. As shown in FIG. 18A, the four individual correction values areset and are greater than or equal to the predetermined number, so theprocess proceeds to step S1503.

In step S1503, it is determined whether the percentage of the number ofindividual correction values in the same direction among the individualcorrection values set for the printing media exceeds a predeterminedpercentage. As for specular reflection value, the individual correctionvalues for standard glossy paper, standard half-glossy paper, andpremium glossy paper are correction values in the positive direction.Since three-quarters, that is, 75% of individual correction values arecorrections in the same direction, the common correction value isupdated in step S1504. Similarly, since 75% of individual correctionvalues for diffused reflection values are corrections in the positivedirection, the common correction value is updated. Since the percentageof the number of individual correction values that are corrections inthe same direction is 50% for paper thickness, the common correctionvalue is not updated.

In step S1504, the common correction values for the characteristicvalues on which the common correction values are updated are updated instep S1503. Of the individual correction values set for specularreflection value, the smallest value is set as a common correction valuefor specular reflection value. In the case of FIG. 18A, +4 is set as thecommon correction value for specular reflection value. Similarly, thecommon correction value for diffused reflection value is set to +2.

In step S1505, the individual correction values are updated based on thecommon correction values set in step S1504. Values obtained by addingthe reference characteristic values of the types of printing media, thecommon correction values, and the individual correction values arecorrected reference values. As for specular reflection value, the commoncorrection value is set to +4, so the individual correction values areupdated with values obtained by subtracting +4 from the set individualcorrection values, and the updated values are as shown in FIG. 18B. Asfor diffused reflection value as well, +2 is subtracted from the setindividual correction values.

Thus, the process of FIG. 17 is ended.

Fifth Embodiment

In the above-described embodiment, even when reference characteristicvalues are updated, the sizes of set detection ranges remain unchanged.In the present embodiment, the sizes of the detection range are changedbased on measured values and reference characteristic values.

FIG. 19 is a flowchart showing a printing medium determination processof acquiring measurement results obtained by measuring thecharacteristics of the printing medium 105 to be printed, providingcandidates for a printing medium to the input/output unit 406 based onthe measurement results, and determining a type of the printing mediumto be printed. In the following printing medium determination process,measured values are obtained as new information for characteristicvalues of a type of printing medium, selected by a user, and thepredetermined characteristic values are changed based on the measuredvalues so as to be brought close to the measured values. Through suchlearning, characteristic values with which a type of the printing mediumcan be more accurately selected are obtained.

The processes of step S1101 to step S1114 are implemented, for example,when the CPU 401 shown in FIG. 4 reads the program stored in the ROM 402onto the RAM 403 and runs the program. The printing medium determinationprocess may be executed by software on the host apparatus. In thepresent embodiment, since the input/output unit 406 is the operationpanel provided in the printing apparatus 100, candidates for a printingmedium are informed by displaying the names of printing media on theoperation panel. The input/output unit 406 may be a combination of thehost apparatus and the display connected to the host apparatus. When theinput/output unit 406 is a speaker that has a microphone function andthat is able to input or output voice, candidates for a printing mediumare informed through the speaker, and a printing medium is selected by auser inputting the name of the printing medium or an associatedreference sign by voice to the microphone.

As the CPU 401 receives an instruction to start sheet feed from a userthrough the operation panel that is the input/output unit 406, the CPU401 starts the printing medium determination process of FIG. 19. FIG. 6Ais an example of display on the operation panel to wait for input of aninstruction to start the sheet feed process. The operation panel is atouch panel with which a user is able to make touch input. When “YES” istouched and sheet feed is started, the printing medium 105 is conveyedby the conveyor roller to a position where the optical sensor 201 isable to detect the printing medium 105 on the platen 106 (step S1101).

After the printing medium 105 is conveyed, the carriage 101 moves in theX direction and the optical sensor 201 moves to above the printingmedium 105 in step S1102.

In step S1103, a specular reflection value V1, diffused reflection valueV2, and printing medium thickness value (hereinafter, paper thickness)V3 of the printing medium 105 are acquired with the optical sensor 201.A diffused reflection value corresponds to the whiteness of a printingmedium. A specular reflection value corresponds to the glossiness of aprinting medium. The printing medium determination process may beexecuted by using the width of a printing medium in the X direction asone of the characteristics of the printing medium. A position where thecharacteristics of a printing medium are measured may be one, or anaverage of measurement results at multiple points may be used.Measurement of the characteristics may be performed in a state where theoptical sensor 201 is stopped or may be performed while the opticalsensor 201 is being moved. Measured values are once stored in a memorysuch as the RAM 403.

Subsequently, in the processes of step S1104 to step S1107, the CPU 401reads the acquired measured values from the memory and compares themeasured values with the predetermined characteristic values of variousprinting media, stored in the EEPROM 404. Thus, types of printing mediaof which a degree to which the characteristic values fall under thecharacteristics indicated by the measured values is higher than apredetermined degree are extracted. Details will be described below.

In step S1104, it is determined whether comparison with thecharacteristic values of all the types of printing media, stored in theEEPROM 404, has completed. When completion is determined, the processproceeds to step S1108.

When it is determined in step S1104 that the comparison has notcompleted, the process proceeds to step S1105, and the characteristicvalues of a type of printing medium are compared with the measuredvalues. FIG. 20A shows the characteristic values of each of the types ofprinting media, stored in the EEPROM 404. The characteristic values areset to predetermined values and are unchanged values. Values obtained byconverting an output voltage from analog to digital with 10 bits arestored as diffused reflection values and specular reflection values. Theoutput voltage is a voltage that the optical sensor 201 outputs uponreceiving light. FIG. 20B shows correction values and learning valuesstored in the EEPROM 404. Learning values will be described later.Correction values are values to be updated through learning. Valuesobtained by correcting the initial values of the predeterminedcharacteristic values shown in FIG. 20A with the correction values shownin FIG. 20B are set as reference characteristic values (hereinafter, thereference values of the characteristic values), these values arecompared with measured values, and the type of printing medium isidentified. In the present embodiment, values obtained by multiplyingthe predetermined characteristic values by the correction values are setas reference characteristic values. For example, the reference value ofthe specular reflection value of plain paper A is expressed by Initialvalue (V1L_a) of specular reflection value×Correction value (α_a). Thetype of a printing medium is detected with an extraction range set to afirst range from a positive extraction limit value to a negativeextraction limit value, shown in FIG. 20C, with reference to thereference value of the characteristic value. For example, the positiveextraction limit value of the specular reflection value of plain paper Ais J1_a and the negative extraction limit value of the specularreflection value of plain paper A is J1′_a, so the extraction range ofthe specular reflection value of plain paper A is from(V1L_a)×(α_a)−(J1′_a) to (V1L_a)×(α_a)+(J1′_a). In step S1105, it isdetermined whether the measured values measured in step S1103 fallswithin the extraction ranges of a printing medium of a predeterminedtype. When the measured values do not fall within the extraction ranges,the process returns to step S1104, and determination is performed on thenext type of printing medium. When the measured values fall within theextraction ranges, the process proceeds to step S1106.

In step S1106, a determination distance Dx that indicates a closenessbetween the measured values and the reference values of thecharacteristic values is calculated. The determination distance Dxindicates that a type of printing medium having reference values ofcharacteristic values of which the determination distance Dx is shorteris closer to the measured type of printing medium. Hereinafter, aformula for calculating the determination distance Dx is shown by usingplain paper A as an example.

Dx={V1−(α_a)×(V1L_a)² +{V2−(β_a)×(V2L_a)}² +{V3−(γ_a)×(V3L_a)}²

A method of finding a determination distance Dx is not limited to theabove-described formula and may be any method in which a similaritybetween measured values and reference values of characteristic valuescan be calculated. In the present embodiment, a distance between allmeasured values to be acquired and reference values of characteristicvalues are collectively found; however, when a correlation therebetweenis low, distances from individual characteristic values may be foundseparately and then closeness to the measured values may be determined.

In step S1107, the determination distance Dx calculated in step S1106and the type of a printing medium are temporarily stored in the RAM 403in association with each other.

When the processes of step S1104 to step S1107 are executed over all thetypes of printing media, affirmative determination is made in stepS1104, and the process proceeds to step S1108. In step S1108, it isdetermined whether there is any type of printing medium stored in theRAM 403. When there is no type of printing medium stored in the RAM 403,all the categories are displayed on the operation panel as shown in FIG.6B (step S111). The categories are arranged in a predetermined order anddisplayed. In the case where the categories are displayed, when acategory selected by a user is input, the types of printing media in thecategory are displayed as shown in FIG. 6C. Then, of the types ofprinting media displayed, the input of the selected type of printingmedium is received. The input is made by touching the name of theprinting medium displayed. FIG. 6B shows “ALL” at the bottom in additionto the categories of printing media. When “ALL” is selected, all theprinting media are displayed in a predetermined order. Recording mediamay be displayed in recent order, that is, in order from the latest usedprinting medium.

When there is a type of printing medium stored in the RAM 403 in stepS1108, the stored type of printing medium is assigned with a priority inascending order of determination distance Dx (step S1109).

As shown in FIG. 6D, the names of the types of printing media aredisplayed from the top in descending order of priority determined instep S1109 (step S1110).

When an icon 40 displayed on the operation panel in FIG. 6D is touched,display of the screen can be scrolled downward. When “STOP” is touched,the printing medium determination process is cancelled, and display ofFIG. 6A is switched to display of a home screen. FIG. 6D shows the namesof printing media in descending order of priority with referencenumerals 1 to 3 prefixed to the names of printing media. Selection of atype of printing medium is made by touching any one of the names ofprinting media displayed. Here, the priority of standard half-glossypaper to which number 1 is assigned is the highest. Codes may be anycodes as long as the codes can indicate the level of priority, and maybe codes other than numerals. A display method is not limited theretoand may be any method as long as a user can recognize the order ofpriority.

In FIG. 6D, candidates for a printing medium can be displayed up tothree from the top; however, since the number of the extracted types ofprinting media is two, only two printing media are displayed in FIG. 6D.A user is informed that there is no third candidate by displaying “NOAVAILABLE CHOICE” in the third field in light color (or dark color) soas to be less attractive than the names of the above-described twoprinting media. For example, when the background color of the operationpanel is black, two printing media are displayed in white color and thetext “NO AVAILABLE CHOICE” is displayed in gray color lower inbrightness than white color. Categories of paper are displayed below thetext “NO AVAILABLE CHOICE”. In this way, when a printing medium that auser desires is not included in printing media displayed on theinput/output unit 406, an individual printing medium is allowed to beselected in order to select a printing medium of another type. In thepresent embodiment, the category to which a type of printing medium inthe first place belongs is displayed at the top. By displayingcategories having close characteristics at higher levels to make it easyto select those categories, even when a printing medium that a userdesires is not included in candidates for a printing medium, time andeffort that take until the category of a desired printing medium isselected can be reduced.

FIG. 8A to FIG. 8C show methods of displaying candidates for a type ofprinting medium on the input/output unit 406 in other modes. As shown inFIG. 8A, when not all the candidates for a type of printing medium canbe displayed on the operation panel, the input/output unit 406 may beconfigured such that a lower-level candidate can be displayed throughscroll operation, or the like. Alternatively, candidates do not need tobe displayed in order from higher level as long as a user can recognizethe order of priority. The name of the highest-level printing medium maybe displayed at the center of the operation panel. Alternatively, asshown in FIG. 8B, the level of priority may be indicated by increasingthe size of characters representing the name of a printing medium havinga higher level of priority or displaying the characters in boldface.Categories are displayed below the text “PAPER CATEGORY”; however,categories may be displayed without any text meaning “PAPER CATEGORY”.Alternatively, not categories but types of printing media other thancandidates for a printing medium may be displayed below the candidates.

Alternatively, as shown in FIG. 8C, only a printing medium having apriority in the first place may be displayed. When a user desires toselect another one of extracted printing media, the user can select aportion of the item of the printing medium displayed as standard plainpaper in FIG. 8C. A display method may be configured such that, when theselection is input, the screen appears as shown in FIG. 6D and anotherprinting medium can be selected.

When a user selects a type of printing medium on the input/output unit406 in step S1112, the correction values are updated with learned valuesin step S1113. A process of updating correction values will be describedlater.

Subsequently, the carriage 101 is moved to a stand-by position in stepS1114. Then, in step S1115, the printing medium 105 is conveyed to thestand-by position for printing with the printing head 102 by theconveyor roller.

Thus, the printing medium determination process ends. When a printingjob is received from the user, printing is started. When the type ofprinting medium selected and input by a user from the input/output unit406 is different from the type of printing medium in a job sent from ahost computer to the printing apparatus 100, the CPU 401 may beconfigured not to update the correction values of the printing medium,stored in the EEPROM 404.

Correction Value Updating Process

FIG. 21 is a flowchart showing the correction value updating process fora printing medium in step S1113 of FIG. 19. Description will be made byway of an example in which a user selects plain paper A in step S1112 ofFIG. 19.

It is determined whether the measured values fall within the learningranges that are a second range of the selected printing medium (here,plain paper A). The learning ranges will be described here. If learningis performed based on a measured value significantly different from areference value of a characteristic value, a wrong value may be learned,so a learning range that is the range of a measured value to be learnedis set. The learning range is a range larger by a predetermined distancefrom the extraction range in the present embodiment. The ranges from thepositive learning limit values to the negative learning limit values,shown in FIG. 20C, are set as learning ranges with reference to thereference values of the characteristic values, and the learning limitvalues are stored in the EEPROM 404. The predetermined distance betweenthe extraction ranges and the learning ranges may be varied among thetypes of printing media. When the measured values fall within thelearning ranges of the selected printing medium, the correction valuesare changed. A predetermined number of measured values are stored in theEEPROM 404 as learning values of plain paper A, and the correctionvalues each are updated based on the learning values. In the presentembodiment, a mode in which two learning values are stored will bedescribed.

In step S1201, it is determined whether the measured specular reflectionvalue V1 falls within the learning range of specular reflection value ofplain paper A. The learning range of specular reflection value of plainpaper A is from (V1L_a)×(α_a)−(L1′_a) to (V1L_a)×(α_a)+(L1_a). When themeasured value does not fall within the learning range, the correctionvalue is not updated, so the correction value updating process is ended.When the measured value falls within the learning range, the processproceeds to step S1202.

In step S1202, it is determined whether the measured diffused reflectionvalue V2 falls within the learning range of diffused reflection value ofplain paper A. The learning range of diffused reflection value of plainpaper A is from (V2L_a)×(β_a)−(L2′_a) to (V2L_a)×(β_a)+(L2_a). When themeasured value does not fall within the learning range, the correctionvalue is not updated, so the correction value updating process is ended.When the measured value falls within the learning range, the processproceeds to step S1203.

In step S1203, it is determined whether the measured paper thickness V3falls within the learning range of paper thickness of plain paper A. Thelearning range of paper thickness of plain paper A is from(V3L_a)×(γ_a)−(L3′_a) to (V3L_a)×(γ_a)+(L3′_a). When the measured valuedoes not fall within the learning range, the correction value is notupdated, so the correction value updating process is ended. When themeasured value falls within the learning range, all the characteristicsfall within the learning ranges, so the measured values are stored inthe EEPROM 404 as learning values, and the process proceeds to stepS1204.

In step S1204, in order to update the learning values stored in theEEPROM 404, it is determined whether last updated learning values arestored in a storage position a2. When the storage position is a2 (YES instep S1204), the learning values stored in a1 are updated with themeasured values in step S1205. When the storage position is a1 (NO instep S1204), the learning values stored in a2 are updated with themeasured values in step S1206. The learning values stored in the EEPROM404 are selected when a printing medium to be printed is plain paper Aand are last and second-last two learning values for which the measuredvalues fall within the learning ranges. The second-last learning valuesthat are the oldest learning values are overwritten and updated withcurrently measured values in step S1204 to step S1206.

In step S1207, average values of the learning values stored in theEEPROM 404 are obtained, percentages by which the average values aredistant from the reference values of the characteristic values arecalculated, the correction values are updated with the percentages.Thus, the correction value updating process is ended.

Extraction Range Changing Process

FIG. 22 shows a flowchart of an extraction range changing process. Theextraction range changing process is executed after the correction valueupdating process of FIG. 21 is ended. This process is to expand orcontract the extraction ranges according to measured values. Theextraction range is changed for each of the characteristics of aprinting medium. Here, description will be made on specular reflectionvalue at the time when a user selects plain paper A. When a measuredvalue does not fall within the extraction range but falls within thelearning range, the measured value is caused to fall within theextraction range through the following process. When a measured valuefalls within the extraction range and the extraction range is relativelywide as compared to the measured value, the extraction range iscontracted.

First, in step S301, it is determined whether the measured value V1 ofspecular reflection, acquired in step S1103 of FIG. 19, is a value thatfalls within the learning range. This can be expressed by the followinginequality.

(V1L_a)×(α_a)−(L1′_a)≤V1≤(V1L_a)×(α_a)+(L1_a)

When the measured value V1 falls outside the learning range, themeasured value V1 is not a value to be learned, so the process ends.When the measured value V1 falls within the learning range, it isdetermined in step S302 whether the measured value V1 is greater thanthe reference value of the characteristic value (V1L_a)×(α_a). Thus, itis determined whether the measured value V1 is a positive-side value ora negative-side value with respect to the reference characteristicvalue.

When the measured value V1 is greater than the reference value of thecharacteristic value (V1L_a)×(α_a) (YES in step S302), the measuredvalue V1 is a positive-side value with respect to the reference value ofthe characteristic value (V1L_a)×(α_a), and the measured value is storedin the EEPROM 404 as V1_n in step S303. A newer measured value is storedin a smaller n. n=N is the largest number, and the oldest measured valueis stored in n=N. When the number of measured values stored in theEEPROM 404 exceeds the maximum value N, the older measured value isdiscarded, and a new value is saved in that place. Here, N=2. In S304, astandard deviation 3σ1 is found from an average V1ave and variance V1varof the N measured values V1 of positive specular reflection. Thestandard deviation 3σ1 is used when the extraction range is expanded instep S308 or contracted in step S311. A formula for finding the standarddeviation 3σ1 is shown below. In the formula, a measured value V1_n ofspecular reflection is denoted by V1n.

$\mspace{20mu} {{V\; 1_{ave}} = \frac{\sum\limits_{n = 1}^{N}{V\; 1_{n}}}{N}}$${V\; 1_{var}} = \frac{\left\{ {\left( {{V\; 1_{ave}} - {V\; 1_{1}}} \right)^{2} + \left( {{V\; 1_{ave}} - {V\; 1_{2}}} \right)^{2} + \ldots + \left( {{V\; 1_{ave}} - {V\; 1_{N}}} \right)^{2}} \right\}}{N}$$\mspace{20mu} {{\sigma 1} = \sqrt{V\; 1_{var}}}$   3σ1 = 3 × σ1

When the measured value V1 is less than or equal to the reference valueof the characteristic value (V1L_a)×(α_a) (NO in step S302), themeasured value V1 is a positive-side value with respect to the referencevalue of the characteristic value (V1L_a)×(α_a), and the measured valueis stored in the EEPROM 404 as V1_n′ in step S305. In S306, a standarddeviation 3σ1 is found from an average V1ave and variance V1var of the Nmeasured values V1_n′ of negative specular reflection.

When the process of step S304 or step S306 ends, it is determined instep S307 whether the measured value falls within the extraction range.When the process proceeds to step S303, it is determined whether V1_1 toV1_N fall within the extraction range. When the process proceeds to stepS305, it is determined whether V1_1′ to V1_N′ fall within the extractionrange.

When any one of the measured values stored in the EEPROM 404 does notfall within the extraction range, the extraction range is expanded instep S308 such that all the measured values fall within the extractionrange. The learning range is also expanded to a range wider inpredetermined distance than the extraction range. To expand theextraction range and the learning range, 3σ1 calculated in step S304 orstep S306 is used. Formulae for changing extraction limit values andlearning limit values to expand the extraction range and the learningrange are shown below.

J1_a=(V1ave+3σ1)

J1′_a=(V1ave−3σ1)

J1_a=(L1_a+(V1ave+3σ1−J1_a))

J1′_a=(L1_a+(V1ave−3σ1−J1_a))

Subsequently, in step S309, it is determined whether the expandedextraction limit value calculated in step S308 is a value greater thanan upper limit value J1max. In the present embodiment, the range ofvalues that the extraction limit values J1_a, J1′_a can take on isdetermined. The size of the range that the learning limit values cantake on is the same as that of the extraction limit values. When theexpanded extraction limit value J1_a is a value greater than the upperlimit value J1max, the extraction range changing process is endedwithout expanding the extraction range. When the expanded extractionlimit value J1_a is not a value greater than the upper limit valueJ1max, the extraction limit value and the learning limit value areupdated with the expanded extraction limit value and expanded learninglimit value calculated in step S308 as a new extraction limit value anda new learning limit value, and the extraction range changing process isended. When any one of the expanded extraction limit value is greaterthan the upper limit value in step S309, the extraction limit value isnot updated; however, the extraction limit value may be updated with theupper limit value as the extraction limit value. The range that theextraction range can take on and the range that the learning range cantake on may be individually provided.

When all the measured values stored in the EEPROM 404 fall within theextraction range in step S307, the extraction range is contracted instep S311 to such a range that all the measured values fall within theextraction range. The learning range is also contracted to such a rangethat is wider in predetermined distance than the extraction range.Similar formulae to those used in step S308 are used to calculateextraction limit values and learning limit values.

Subsequently, in step S312, it is determined whether the contractedextraction limit value calculated in step S311 is a value less than alower limit value J1min. When the contracted extraction limit value J1_ais less than the lower limit value Jmin, the extraction range changingprocess is ended without contracting the extraction range. When thecontracted extraction limit value J1_a is not a value less than thelower limit value J1min, the extraction limit value and the learninglimit value are updated with the contracted extraction limit value andcontracted learning limit value calculated in step S311 as a newextraction limit value and a new learning limit value, and theextraction range changing process is ended.

The above-described extraction range changing process is similarlyexecuted on diffused reflection value and paper thickness.

In the present embodiment, the standard deviation 3σ is used to expandor contract the ranges. When the standard deviation 3σ is used, a rangein which 99.7% of all the measured values stored in the EEPROM 404 fallcan be calculated. A value other than 3a may be used as a standarddeviation according to the percentage of measured values intended to beincluded in the range among all the measured values stored in the EEPROM404.

Sixth Embodiment

In the present embodiment, a method of determining extraction limitvalues and learning limit values for a printing medium of whichcharacteristic values are not prestored in the EEPROM 404 will bedescribed.

In the present embodiment, when a user desires to use a printing mediumof which characteristic values are not prestored in the EEPROM 404,characteristic values, extraction limit values, and learning limitvalues are set for the intended type of printing medium. Thus, the printmedium can be extracted as a candidate for a printing medium in theprinting medium determination process of FIG. 19.

As for the characteristic values of an intended printing medium, first,a user selects the closest type of printing medium of the prestoredprinting media. The characteristic values set for the selected type ofprinting medium are set for the characteristic values of the intendedprinting medium.

As for the extraction range and learning range of the intended printingmedium, such extraction limit values and learning limit values that theextraction range and the learning range have the same size as theextraction range and learning range of the type of printing mediumhaving the widest extraction range of the prestored printing media areset.

The characteristic values may be acquired by measuring an intendedprinting medium with the optical sensor 201.

Seventh Embodiment

In the first embodiment and the second embodiment, characteristic valuesare changed based on measured values. However, it is conceivable thatcharacteristic values are not changed so as to increase the accuracy ofextracting a type of printing medium. For example, it is presumable thata user may erroneously select a type of printing medium different from adesired printing medium. In such a case, the characteristic values of anerroneously selected printing medium are changed based on measuredvalues, so a type of printing medium may not be accurately extractedwith the changed characteristic values.

In the above-described situation, it is also presumable that the changedcharacteristic values may be reset. The present embodiment describes amode in which changed characteristic values are reset. When the printingapparatus 100 is used by a plurality of users, characteristic values maybe reset retroactively to changes of characteristic values resultingfrom the usage of a former user. A mode in which characteristic valuescan be reset to initial values will be described as an example. Initialvalues here are characteristic values of printing media prestored in theEEPROM 404 when the printing apparatus 100 is used by a user for thefirst time.

Description will be made on the assumption that a printing apparatus ofthe present embodiment is the printing apparatus described in the secondembodiment, which displays a candidate for a printing medium based onhistory information. The description of portions similar to those of theabove-described embodiments is omitted. In the printing mediumdetermination process, when a user erroneously selects a type ofprinting medium, a recommendation for resetting data of learnedcharacteristic values may be informed. A user is prompted to resetthrough notification, and informing an incorrectly extracted candidatecan be prevented.

FIG. 23 shows a flowchart of a resetting process. The resetting processis a process that the CPU 401 executes in accordance with a programstored in the ROM 402.

Both characteristic values of types of printing media, prestored asinitial values, as shown in FIG. 7A, and learned characteristic valuesof types of printing media, changed through learning, as shown in FIG.7B, are stored in the EEPROM 404. Characteristic values to be changedthrough learning are shown in FIG. 7B. In the printing mediumdetermination process of FIG. 13, the learned characteristic valuesshown in FIG. 7B are compared with the measured values measured with theoptical sensor 201, and a candidate for a type of printing medium isextracted. Characteristic values stored as initial values are notchanged. The process of resetting learned characteristic values toinitial values are executed by storing the initial values of thecharacteristic values, stored in the EEPROM 404, in areas where thelearned characteristic values are stored.

In the present embodiment, an “estimated data resetting” process ofresetting learned characteristic values that are data for estimating atype of printing medium to initial values and a “paper informationresetting” process of resetting all information set on types of printingmedia to be reset can be executed. Hereinafter, data of learnedcharacteristic values are also referred to as estimated data. The paperinformation resetting process is a process of resetting informationassociated with all the printing media to an initial state, and includesa process of clearing information stored as history information byresetting the history information in addition to a process of resettinglearned characteristic values to initial values. Alternatively, as inthe case of the third embodiment, a mode in which characteristic valuesand correction values of printing media are provided is also applicable.In this case, estimated data is reset by resetting correction values toinitial values.

First, in step S1601, a home screen (FIG. 24A) is displayed on theinput/output unit 406. FIG. 24A shows a state when “MAIN SETTINGS” isselected from among the items displayed on the home screen. When an itemis selected, the selected item is highlighted, and the next screen isdisplayed. In FIG. 24A to FIG. 24H, the item is highlighted such thatthe background of the item is varied in color from the other items andthe frame of the item is widened.

When “MAIN SETTINGS” is selected on the home screen, a main settingsscreen as shown in FIG. 24B is displayed on the input/output unit 406 instep S1602. When “PAPER-RELATED SETTINGS” is selected on the mainsettings screen, “PAPER-RELATED SETTINGS” is highlighted as shown inFIG. 24B, and a paper-related settings screen as shown in FIG. 24C isdisplayed in step S1603. FIG. 24C shows a state when “DETAILED PAPERSETTINGS” is selected on the settings screen. On the paper-relatedsettings screen, items for setting printing medium information in theprinting apparatus 100 are displayed. The items include, for example, anitem for setting the level of the printing head 102 at the time ofprinting and an item for setting a cut speed at the time of cuttingrolled paper.

When a user desires to reset learned characteristic values for all thetypes of printing media, the user selects “RESET ALL ESTIMATED DATA OFPAPER SELECTION” on the paper-related settings screen. When “RESET ALLESTIMATED DATA OF PAPER SELECTION” is selected, the learnedcharacteristic values of all the types of printing media are reset tothe initial values shown in FIG. 7A, stored in the EEPROM 404, in stepS1604. A process of resetting all the estimated data will be describedin detail later.

When a user desires to reset all the printing medium information aboutprinting media, the user selects “RESET ALL PAPER INFORMATION”. When“RESET ALL PAPER INFORMATION” is selected, initilizable data includingcharacteristic values and history information are reset to the initialvalues in step S1605. A process of resetting all the printing mediuminformation will be described in detail with reference to FIG. 26.

When a user desires to reset learned values or history information ofcharacteristic values for each type of printing medium, “DETAILED PAPERSETTINGS” is selected. When “DETAILED PAPER SETTINGS” is selected,characteristic values and history information for each type of printingmedium is reset in step S1606. This will be described in detail laterwith reference to FIG. 27.

Thus, the resetting process is ended.

The process of resetting all the estimated data of paper selection instep S1604 of FIG. 23 will be described. FIG. 25 is a flowchart showingthe process of step S1604.

When “RESET ALL ESTIMATED DATA OF PAPER SELECTION” is selected on thepaper-related settings screen (FIG. 24C), a confirmation screen as shownin FIG. 24G is displayed in step S1801. When “YES” is selected on theconformation screen (Yes in step S1802), the learned characteristicvalues of all the printing media are reset to the initial values in stepS1803. Subsequently, the paper-related settings screen is displayed onthe input/output unit 406 in step S1805, and the process is ended.

When “YES” is not selected (No in step S1802) and “NO” is selected (Yesin step S1802) on the confirmation screen, the paper-related settingsscreen is displayed on the input/output unit 406 in step S1805, and theprocess is ended. When “YES” is not selected (No in step S1802) and “NO”is not selected (No in step S1804) on the confirmation screen, theconfirmation screen is displayed until one of both is selected.

The process of resetting all the estimated data of paper selection isexecuted as described above.

Next, the process of resetting all the printing medium information instep S1605 of FIG. 23 will be described. FIG. 26 is a flowchart showingthe process of step S1605.

When RESET ALL PAPER INFORMATION” is selected on the paper-relatedsettings screen (FIG. 24C), a confirmation screen as shown in FIG. 24His displayed in step S1901. When “YES” is selected on the conformationscreen (Yes in step S1902), the printing medium information set for allthe types of printing media is set to the initial values in step S1903.The printing medium information contains not only characteristic valuesand history information of types of printing media but also, forexample, the setting of the level of the printing head 102 at the timeof printing, a cut speed at the time of cutting rolled paper, and thelike. Subsequently, the paper-related settings screen is displayed onthe input/output unit 406 in step S1905, and the process is ended.

When “YES” is not selected (No in step S1902) and “NO” is selected (Yesin step S1904) on the confirmation screen, the paper-related settingsscreen is displayed on the input/output unit 406 in step S1905, and theprocess is ended. When “YES” is not selected (No in step S1902) and “NO”is not selected (No in step S1904) on the confirmation screen, theconfirmation screen is displayed until one of both is selected.

The process of resetting all the printing medium information of paperselection is executed as described above.

Next, the resetting process for each type of printing medium in stepS1606 of FIG. 23 will be described. FIG. 27 is a flowchart showing theprocess of step S1606.

When “DETAILED PAPER SETTINGS” is selected on the paper-related settingsscreen (FIG. 24C), a screen for selecting a type of printing medium asshown in FIG. 24D is displayed in step S2001. In FIG. 24D, a category ofa printing medium can be selected. FIG. 24D shows a state where thecategory of plain paper is selected. For example, when the category ofplain paper is selected, “STANDARD PLAIN PAPER” AND “PREMIUM PLAINPAPER” that are types of printing media that belong to the category ofplain paper are displayed in step S2002 (FIG. 24E). FIG. 24E shows astate when standard plain paper is selected.

When a type of printing medium is selected in step S2002, a detailedsettings screen for the type of printing medium selected in step S2003is displayed as shown in FIG. 24F. FIG. 24F shows a state when “RESETESTIMATED DATA OF PAPER SELECTION” is selected. The outer diameter ofpaper tube, the thickness of paper, and the like, can be set for eachtype of printing medium from the screen of FIG. 24F. Learned values ofcharacteristic values of a type of printing medium can be reset orprinting medium information can be reset from this screen.

When “RESET ESTIMATED DATA OF PAPER SELECTION” is selected on the screenof FIG. 24F, the process of resetting estimated data and setting learnedcharacteristic values of the type of printing medium to initial valuesis executed in step S2004. The process of step S2004 is similar to theabove-described process of FIG. 25, and the characteristic values of aselected type of printing medium are reset to initial values in stepS1803.

When “RESET PAPER INFORMATION” is selected on the screen of FIG. 24F,all data including characteristic values and history information isreset to initial values in step S2005. The process of step S2005 issimilar to the above-described process of FIG. 26, and paper informationset for the selected type of printing medium is reset to initial valuesin step S1903. Only the history information of the type of printingmedium to be reset is deleted, and the history information of the othertypes of printing media remains stored.

When the process of step S2004 or step S2005 completes, the processproceeds to step S2006, and displays a screen for selecting whether toexecute the resetting process on another type of printing medium. Whenreset is selected, the process returns to step S2001. When no reset isselected, the detailed settings screen (FIG. 24F) on the selected typeof printing medium is displayed as in the case of step S2003, and theprocess is ended.

In the above description, characteristic values of a type of printingmedium are set to initial values by the process of resetting estimateddata, and characteristic values of a type of printing medium are set toinitial values and history information is reset by the process ofresetting printing medium information. By resetting characteristicvalues to initial values, a decrease in the accuracy of extractingcandidates for a type of printing medium can be prevented, soinconvenience of a user can be reduced.

Alternatively, a process of resetting only history information may beexecuted. For example, when a person who uses the printing apparatus 100has changed, it is conceivable that, even when candidates for a type ofprinting medium are displayed based on history information, typesdifferent from types of printing media that the new person frequentlyuses may be displayed as higher-level candidates. In such a case, whenlearned characteristic values of types of printing media are not resetand only history information is reset, a printing medium can beextracted with an increased accuracy, so the convenience of usersimproves.

Changes of characteristic values are reset and the characteristic valuesof printing media are set to initial values; however, changes do notneed to be returned to initial values. For example, last changes or lastseveral-time changes may be reset. The timing of resetting changes ofcharacteristic values may be other than when a user inputs informationfor resetting. Reset may be performed, for example, when an environmentin which the printing apparatus 100 is used has changed or when a userwho uses the printing apparatus 100 has changed.

OTHER EMBODIMENTS

In the above-described embodiments, a specular reflection value, adiffused reflection value, and a paper thickness are acquired ascharacteristics, and a type of printing medium is extracted constantlybased on those three characteristic values. However, in some cases,characteristics to be acquired may be changed. For example, the numberof characteristics to be acquired may be reduced, and a type of printingmedium may be extracted based on only a specular reflection value and adiffused reflection value. When sufficient learning is performed andreference characteristic values are sufficiently closer to measuredvalues, it may be determined that a type of printing medium can beaccurately extracted. In this case, the number of characteristics to beacquired is reduced. Since the number of characteristics for measuredvalues to be acquired and compared with reference characteristic valuesreduces, the duration of the process can be reduced.

Embodiments of the present invention can also be realized by a computerof a system or apparatus that reads out and executes computer executableinstructions (e.g., one or more programs) recorded on a storage medium(which may also be referred to more fully as a ‘non-transitorycomputer-readable storage medium’) to perform the functions of one ormore of the above-described embodiments and/or that includes one or morecircuits (e.g., application specific integrated circuit (ASIC)) forperforming the functions of one or more of the above-describedembodiments, and by a method performed by the computer of the system orapparatus by, for example, reading out and executing the computerexecutable instructions from the storage medium to perform the functionsof one or more of the above-described embodiments and/or controlling theone or more circuits to perform the functions of one or more of theabove-described embodiments. The computer may comprise one or moreprocessors (e.g., central processing unit (CPU), micro processing unit(MPU)) and may include a network of separate computers or separateprocessors to read out and execute the computer executable instructions.The computer executable instructions may be provided to the computer,for example, from a network or the storage medium. The storage mediummay include, for example, one or more of a hard disk, a random-accessmemory (RAM), a read only memory (ROM), a storage of distributedcomputing systems, an optical disk (such as a compact disc (CD), digitalversatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, amemory card, and the like.

According to embodiments of the present invention, there is a higherpossibility that a type of printing medium can be accurately identified.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Applications No.2019-036835, filed Feb. 28, 2019, No. 2019-063890, filed Mar. 28, 2019,and No. 2019-068050, filed Mar. 29, 2019, which are hereby incorporatedby reference herein in their entirety.

What is claimed is:
 1. An information processing apparatus comprising:an acquisition unit configured to acquire a measurement result obtainedby measuring a characteristic value of a printing medium with ameasuring unit, the printing medium to be printed with a printing unit;a decision unit configured to decide a candidate for a type of theprinting medium based on the measurement result of the printing medium,acquired by the acquisition unit, and a reference characteristic valueof each of types of printing media set in advance to identify a type ofthe measured printing medium; an input unit configured to inputinformation associated with the type of the printing medium to beprinted with the printing unit; a determination unit configured todetermine whether to change the reference characteristic value of thetype of the printing medium associated with the information input by theinput unit based on the measurement result of the printing medium andthe type of the printing medium associated with the information input bythe input unit; and a change unit configured to, when the determinationunit determines to change the reference characteristic value of the typeof the printing medium associated with the information input by theinput unit, change the reference characteristic value of the type of theprinting medium associated with the information input by the input unitbased on the measurement result of the printing medium.
 2. Theinformation processing apparatus according to claim 1, wherein thechange unit is configured to change the reference characteristic valueof the type of the printing medium associated with the information inputby the input unit such that the reference characteristic valueapproaches the measurement result.
 3. The information processingapparatus according to claim 2, wherein the reference characteristicvalue set in advance for each of the types of the printing media is avalue including an upper limit value and a lower limit value, and thechange unit is configured to change the reference characteristic valuesuch that a central value of the reference characteristic valueapproaches the measurement result.
 4. The information processingapparatus according to claim 1, wherein the change unit is configuredto, when information associated with another one of the types of theprinting media, different from the type of the printing medium of thecandidate decided by the decision unit, is input by the input unit,change the reference characteristic value of the another one of thetypes of the printing media, associated with the information input bythe input unit.
 5. The information processing apparatus according toclaim 2, wherein a correction value for changing the referencecharacteristic value set in advance for each of the types of theprinting media to the reference characteristic value associated with acorresponding one of the types of the printing media is provided, andthe change unit is configured to change the correction value.
 6. Theinformation processing apparatus according to claim 1, furthercomprising a notification control unit configured to cause anotification unit to provide information indicating the candidate forthe type of the printing medium, decided by the decision unit.
 7. Theinformation processing apparatus according to claim 6, wherein thenotification control unit is configured to cause the notification unitto preferentially provide information indicating the type of theprinting medium of which the reference characteristic value is closer tothe measurement result, of the types of the printing media of which thereference characteristic values are set in advance.
 8. The informationprocessing apparatus according to claim 7, wherein the notificationcontrol unit is configured to cause the notification unit to provideinformation indicating the types of the printing media, of which thereference characteristic values are set in advance, in order ofcloseness of the reference characteristic value to the measurementresult.
 9. The information processing apparatus according to claim 6,wherein the notification control unit is configured to preferentiallyprovide the printing medium of which printed timing is closer, based onusage history information indicating a type of a printing medium printedwith the printing unit.
 10. The information processing apparatusaccording to claim 6, wherein the reference characteristic value set inadvance for each of the types of the printing media has a referencevalue, and the notification control unit is configured to cause thenotification unit to provide information indicating the type of theprinting medium having such a reference characteristic value that adifference between the measurement result and the reference value of thereference characteristic value is less than or equal to a first value.11. The information processing apparatus according to claim 6, whereinthe reference characteristic value set in advance for each of the typesof the printing media has a reference value, and the notificationcontrol unit is configured to cause the notification unit to provideinformation indicating the type of the printing medium having such areference characteristic value that the measurement result falls withina first range including the reference value of the referencecharacteristic value.
 12. The information processing apparatus accordingto claim 11, wherein the change unit is configured to expand or contractthe first range of the type of the printing medium indicated by theinformation input by the input unit based on the measurement result. 13.The information processing apparatus according to claim 12, wherein thechange unit is configured to change one of an upper limit value andlower limit value of the first range.
 14. The information processingapparatus according to claim 11, wherein the determination unit isconfigured to, when the measurement result falls within a second rangethat includes the reference value of the type of the printing mediumindicated by the information input by the input unit and that is a rangewider than or equal to the first range, determine to cause the changeunit to change the reference characteristic value of the type of theprinting medium associated with the information input by the input unit.15. The information processing apparatus according to claim 14, whereinthe change unit is configured to, when the measurement result fallsoutside the first range of the type of the printing medium indicated bythe information input by the input unit and falls within the secondrange, expand the first range in a direction toward the measurementresult.
 16. The information processing apparatus according to claim 12,wherein the change unit is configured to, when the measurement resultfalls within the first range, contract the first range in a directiontoward the measurement result such that the measurement result isincluded.
 17. The information processing apparatus according to claim14, wherein the change unit is configured to change an upper limit valueand lower limit value of the second range.
 18. The informationprocessing apparatus according to claim 1, wherein the change unit isconfigured to change a reference value of the reference characteristicvalue of the type of the printing medium such that the reference valueapproaches the measurement result by a predetermined percentage.
 19. Theinformation processing apparatus according to claim 1, wherein thechange unit is configured to set an average of the measurement resultswhen the information associated with the type of the printing medium isinput by the input unit for the reference characteristic valueassociated with the type of the printing medium.
 20. The informationprocessing apparatus according to claim 6, wherein the determinationunit is configured to, when the information associated with thecandidate for the type of the printing medium, which the notificationcontrol unit has caused the notification unit to provide, is input bythe input unit, determine to cause the change unit to change thereference characteristic value of the type of the printing medium, inputby the input unit.
 21. The information processing apparatus according toclaim 1, wherein the characteristic value of the printing medium, whichthe measurement unit measures, includes at least one of a diffusedreflection value, specular reflection value, and thickness value of theprinting medium.
 22. The information processing apparatus according toclaim 6, wherein the notification control unit is configured to causethe notification unit to provide a name of the printing medium.
 23. Theinformation processing apparatus according to claim 5, wherein inaddition to the correction value, a common correction value forcorrecting characteristic values of types of a plurality of printingmedia is provided, a reference characteristic value associated with thetype of the printing medium is calculated by correcting the referencecharacteristic value set in advance for each of the types of theprinting media based on the associated correction value and the commoncorrection value, and the change unit is configured to correct thecommon correction value based on the correction values of the types ofthe plurality of printing media.
 24. The information processingapparatus according to claim 1, wherein the change unit is configuredto, based on the measurement result, change a type of a characteristicvalue of a measurement result that the acquisition unit acquires. 25.The information processing apparatus according to claim 1, wherein theinput unit is configured to be able to input information indicating thatthe reference characteristic value changed by the change unit is reset.26. The information processing apparatus according to claim 25, wherein,when, for a predetermined one of the types of the printing media,information indicating that the reference characteristic value changedby the change unit is reset is input by the input unit, the change unitis configured to execute a process of resetting the referencecharacteristic value changed by the change unit for the predeterminedone of the types of the printing media.
 27. The information processingapparatus according to claim 25, wherein the information indicating thatthe changed reference characteristic value is reset is reset informationindicating that all the reference characteristic values changed by thechange unit are reset, and when the reset information is input by theinput unit, the change unit is configured to reset all the referencecharacteristic values changed by the change unit.
 28. The informationprocessing apparatus according to claim 1, wherein the input unit isconfigured to be able to input information about a printing apparatusincluding the printing unit for controlling the printing apparatus andinformation indicating that changed information about the printingapparatus is reset, when the information about the printing apparatus isinput by the input unit, the change unit is configured to change theinformation about the printing apparatus in accordance with the inputinformation and set the changed information, and when the informationindicating that the changed information about the printing apparatus isreset is input by the input unit, the change unit is configured to resetthe information about the printing apparatus.
 29. The informationprocessing apparatus according to claim 1, wherein the input unit isconfigured to be able to input information to reset usage historyinformation indicating a type of a printing medium that has been printedwith the printing unit.
 30. The information processing apparatusaccording to claim 29, wherein, when the information to reset the usagehistory information is input by the input unit, the change unit isconfigured to delete the usage history information.
 31. The informationprocessing apparatus according to claim 1, further comprising: theprinting unit configured to apply a recording agent to a printingmedium; and a conveyance unit configured to convey a printing medium toa position where printing is performed, wherein when the conveyance unitconveys the printing medium to a position where the printing unit isable to print, the printing unit is configured to print on the printingmedium.
 32. The information processing apparatus according to claim 31,further comprising a carriage loaded with the printing unit andconfigured to be movable, wherein the measurement unit is mounted on thecarriage and is configured to measure a characteristic value of theprinting medium conveyed by the conveyance unit to a position where themeasurement unit is able to perform measurement.
 33. An informationprocessing method comprising: measuring a characteristic value of aprinting medium to be printed with a printing unit; extracting acandidate for a type of the printing medium measured based on thecharacteristic value, and a reference characteristic value set inadvance for each of types of printing media to identify a type of themeasured printing medium; inputting information associated with the typeof the printing medium to be printed with the printing unit; changingthe reference characteristic value of the type of the printing mediumassociated with the information input in determining the type of theprinting medium, based on the characteristic value; and determiningwhether to change the reference characteristic value of the type of theprinting medium based on the measurement result and the type of theprinting medium associated with the information input in determining thetype of the printing medium.
 34. A non-transitory computer-readablestorage medium storing a program for causing a computer to execute aprocess, the process comprising: acquiring a measurement result obtainedby measuring a characteristic value of a printing medium to be printedwith a printing unit; extracting a candidate for a type of the printingmedium measured based on an acquired measurement result, and a referencecharacteristic value set in advance for each of types of printing mediato identify a type of the measured printing medium; inputtinginformation associated with the type of the printing medium to beprinted with the printing unit; changing the reference characteristicvalue of the type of the printing medium associated with the informationinput in determining the type of the printing medium, based on themeasurement result; and determining whether to change the referencecharacteristic value of the type of the printing medium based on themeasurement result and the type of the printing medium associated withthe information input in determining the type of the printing medium.